tbuckley/cabot-search huggingface dataset:
Abstract 6368: Preclinical pharmacology and safety studies of ZG005: an anti-PD-1/TIGIT bispecific mAb in a phase I clinical trial for advanced tumors
Authors: Bing Zhu, Tongcheng Dai, Ruifeng Liu, Alfonso Suarez, Tyler Liban, Bin Zhang, Margaret Karow, Jackie Sheng, Zelin Sheng, Binhua Lv
Journal: Cancer Research (2023)

Abstract ZG005 is a humanized anti-PD-1/TIGIT bispecific antibody that effectively blocks the binding between PD-1 and TIGIT, on immune cells, with their specific ligands PD-L1 and PVR, on tumors. As a dual blockade of PD-1/TIGIT immune checkpoints, ZG005 exhibits sustained occupancy to both targets and inhibits their pathways specifically and simultaneously, leading to synergistic effects and boosting the ability of the immune system in killing tumor cells. With high binding affinities, ZG005 elicits the activation of T cells and NK cells resulting in increased release of cytokines and the depletion of Tregs, independent of ADCC activities. ZG005 utilizes the IgG4 isotype to avoid the potential negative impact of effector function and target-crosslinking that has been reported for anti-TIGIT therapeutics using IgG1 isotype. In vivo animal studies indicate that ZG005 has potent and dose-dependent anti-tumor efficacies in syngeneic models using CT26 and MC38 colon tumors in humanized PD-1/TIGIT dKIs mice. In these models, the whole blood and TIL analyses confirmed increases in CD8+ and NK cells but reduction of Treg cell levels after ZG005 treatments. The combination of ZG005 with chemotherapeutic-reagents, cisplatin and donafenib, enhanced their anti-tumor efficacies. Toxicity and safety pharmacology studies with weekly repeat doses for four weeks in cynomolgus monkeys, indicate that ZG005 is well tolerated. Over the dose range 20-180 mg/kg, there were no obvious toxic or adverse effects, and the HNSTD and NOAEL values were 180 mg/kg and 60 mg/kg, respectively. PK/TK analyses indicate a prolonged ZG005 receptor occupancy over 80%, consistent with in vitro binding results that are attribute to the S228P mutation in the IgG4 hinge region to prevent Fab exchange and enhance stability. The IND application of ZG005 has been approved by both FDA and NMPA, and the molecule is currently in phase I clinical trials for advanced solid tumors at escalated dosing of 0.3~20 mg/kg, Q3W, via i.v. administration. Citation Format: Bing Zhu, Tongcheng Dai, Ruifeng Liu, Alfonso Suarez, Tyler Liban, Bin Zhang, Margaret Karow, Jackie Sheng, Zelin Sheng, Binhua Lv. Preclinical pharmacology and safety studies of ZG005: an anti-PD-1/TIGIT bispecific mAb in a phase I clinical trial for advanced tumors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6368.
Abstract 751: Disparities in physician office visit wait time among US cancer survivors
Authors: Onyema Chido-Amajuoyi, Ikenna Nnamani, Owhofasa Agbedia
Journal: Cancer Research (2023)

Abstract Background: Disparities are well-documented in the time spent seeking medical care in the US. Studies have found that minority populations are likely to have longer wait times securing healthcare access and higher total time spent at clinic visits. However, this relationship has not been previously examined among the cancer survivor population, which constitutes about 17 million people in the US. Methods: Study data were derived from the 2018 National Health Interview Survey, a nationally representative survey of US adults. Study sample was restricted to cancer survivors (n=2,940; N=23,310,174). The primary outcome of this study was reports of prolonged wait times during doctor office visits. Weighted multivariable logistic regression were used to estimate adjusted associations between prolonged wait times during doctor office visits and sociodemographic and behavioral characteristics of cancer survivors. All analyses were conducted using STATA version 14.2. Results: Respondents who identified as Black/African American were almost 3 times more likely than their White counterparts to report prolonged wait times during doctor office visits (aOR 2.65, 95% CI; 1.296, 5.419). Similarly, respondents who identified as Hispanic were almost 3 times more likely than non-Hispanic respondents to report prolonged wait times during doctor office visits (aOR 2.604, 95% CI; 1.347, 5.035). Respondents in the $50,000 - $74,999 income bracket were less likely to report prolonged wait times during doctor office visits than respondents who earned less than $35,000 (aOR: 0.50, 95% CI, 0.276, 0.916). Conclusion: Black/African American and Hispanic cancer survivors had increased odds of reporting prolonged wait times during doctor office visits. Disparities in cancer health and survivorship are well documented among racial minorities. Addressing disparities in healthcare experiences and access will be crucial in dispelling existing cancer health disparities. Citation Format: Onyema Chido-Amajuoyi, Ikenna Nnamani, Owhofasa Agbedia. Disparities in physician office visit wait time among US cancer survivors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 751.
Abstract 6370: Cell-based luminescent reporter bioassays for immunotherapies targeting macrophage effector functions
Authors: Jonathan Mitchell, Julia Gilden, Jim Hartnett, Pete Stecha, Gopal B. Krishnan, Frank Fan, Mei Cong, Jamison Grailer
Journal: Cancer Research (2023)

Abstract Macrophages play a key role in the elimination of cancer via phagocytosis and presentation of tumor antigens to T cells. Antibody-dependent cellular phagocytosis (ADCP), mediated by macrophages and other myeloid cells, is an important mechanism-of-action (MoA) for antibody-based cancer immunotherapies. Therapeutic strategies that enhance ADCP and other macrophage effector functions can augment direct tumor destruction and enable anti-tumor immunity. ADCP is initiated by binding of antibody Fc domains to Fc gamma receptors (FcgRs), and FcgR crosslinking results in signal transduction that drives inflammatory cytokine production and phagocytosis. Simultaneously, macrophage effector functions are regulated by immune checkpoints. Blockade of these immune checkpoints (e.g., SIRPa, ILT4), or agonists of activation pathways (e.g., TLR receptors) can enhance macrophage effector functions. Current assays to measure macrophage function are tedious, low throughput, and highly variable. Here, we present a suite of cell-based luminescent reporter bioassays to measure macrophage effector functions: 1) A monocytic cell background was used to measure ADCP via endogenous expression of multiple FcgRs and integration of a FcgR-activation dependent luminescent reporter. 2) Direct detection of cellular phagocytosis can be measured using the HiBiT split luciferase system. 3) Modulation of macrophage-expressed immune checkpoints can be determined using cell-based reporter bioassays for SIRPa/CD47 and ILT4/HLA-G. 4) Activation of TLRs 1, 2, 4, 5 and 6 can be measured using a TLR reporter bioassay. These bioassays are robust, easy-to-use, and are pre-qualified according to ICH guidelines. Together, these novel reporter bioassays provide a robust, high-throughput toolbox to facilitate discovery and development of immunotherapies targeting macrophage effector functions. Citation Format: Jonathan Mitchell, Julia Gilden, Jim Hartnett, Pete Stecha, Gopal B. Krishnan, Frank Fan, Mei Cong, Jamison Grailer. Cell-based luminescent reporter bioassays for immunotherapies targeting macrophage effector functions. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6370.
Abstract 3628: <i>RAC1</i> aberrations in head and neck cancer affect immune microenvironments
Authors: Helen Hoi Yin Chan, Yuchen Liu, Hoi Lam Ngan, Vivian Wai Yan Lui
Journal: Cancer Research (2023)

Abstract RAC1 is a Rho GTPase well-identified as an oncogene overexpressed in various cancer types. RAC1 amplification or gain account for ~40% of head and neck squamous cell carcinoma (HNSCC) while mutation of RAC1 occurs at ~3% according to TCGA-HNSCC cohort. HNSCC patients with RAC1 aberrations, including RAC1 mutations and amplification or gain, are associated with poor overall and disease-free survival in HNSCC. Significantly higher tumor mutational burden is observed in RAC1-mutated group (p=0.0336) or in RAC1-amplified/gain group (p=0.0109) vs. wildtype patients in TCGA-HNSCC cohort. As increases in TMB are often associated with immune cell infiltration in cancers, we hypothesized that RAC1 aberrations impact the tumor immune microenvironment (TIME) of HNSCC, potentially contributing to disease progression.PD-L1 (CD274) is an important immunosuppressive immune checkpoint molecule expressed in tumor cells. Here, we first reported that ectopic overexpression of RAC1 p.P29S and p.A159V mutations in a human HNSCC cell line (PECAPJ41 clone D2, ATCC, USA) could cause upregulation of PD-L1 at both mRNA (by RNA-seq) and protein levels (by Western blotting), first demonstrating a direct effect of RAC1 mutations on potential HNSCC TIME modulation via PD-L1. Furthermore, by tumor immune estimation resources (TIMER) analysis, we found that RAC1-mutated tumors have significantly higher level of neutrophils immune infiltration of 38.63% (p=0.027) compared to the wildtype tumors. From the CIBERSORTx analysis, M2 Macrophages was significantly increased by 40.42% in RAC1-mutated tumors vs wildtype in the TCGA-HNSCC cohort (p=0.031). We also validated this finding by immunofluorescent staining of PD-L1 and M2 Macrophages in immunocompetent mouse HNSCC xenografts models expressing RAC1 p.P29S and p.A159V mutations as compared to controls. Our in silico, in vitro and in vivo findings first uncover an important role of RAC1 aberrations in HNSCC TIME immunosuppression by regulating PD-L1 expression, neutrophil and M2 macrophages infiltrations. Clinical activities of PD-L1 inhibitors in RAC1-mutated HNSCC patients worth future investigations. Acknowledgement: This research is funded by the General Research Fund (Ref. No.:14168517) and the Research Impact Fund (Ref. No.: R4015-19) from the Research Grants Council in Hong Kong. VWYL is supported by Start-up Fund, Georgia Cancer Center, Medical College of Georgia at Augusta University. Citation Format: Helen Hoi Yin Chan, Yuchen Liu, Hoi Lam Ngan, Vivian Wai Yan Lui. RAC1 aberrations in head and neck cancer affect immune microenvironments. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3628.
Abstract 1242: Single cell multiomic map reveals regulatory landscape of human brain metastases
Authors: Remi Klotz, Alexis Zukowski, Mohamed Kamal, Frank Attenelo, Srinivas Ramachandran, Min Yu
Journal: Cancer Research (2023)

Abstract Capturing comprehensive brain metastasis landscape is critical to the establishment of effective anti-tumor strategies. This study took advantage of single-cell multiomics sequencing to profile the molecular and cellular dynamics in tumor cells and associated microenvironment during brain metastasis. Among different primary cancer types, our data suggest that there are conserved yet distinct tumor cell subpopulations, governed by specific changes in gene expression, chromatin accessibility and tumor-stroma interactions. We characterized the conserved tumor subpopulations of brain metastasis with features of: (1) dormancy, (2) enhanced translation and migration, (3) cell death and (4) high proliferation rate. Dormant tumor cells in brain metastasis appear to limit cell-cell interactions with the surrounding microenvironment. In line with previous observations, dormant cells exhibit distinct stimulation for interferon, oxidative phosphorylation and HIPPO signaling. Despite a pronounced cell plasticity, trajectory analysis uncovered a cell progression pattern and its major sequential states and driving genes. Importantly, the tumor trajectory provides new insights into the regulatory landscape controlling the transition from dormant to proliferating tumor cells. Our findings also point to a valuable use of matched isolated circulating tumor cells and cell-free DNA to map the molecular and cellular dynamics of brain metastases. This work demonstrated that despite a pronounced intratumoral heterogeneity, brain metastases present conserved tumor subpopulations regardless of the patient and primary type. A novel and key finding in this study is the multiomics characterization of the regulatory landscape shaping human brain metatastases. Thus, we believe further understanding of these key regulatory elements could lead to novel tumor targets with broad translational potential. Citation Format: Remi Klotz, Alexis Zukowski, Mohamed Kamal, Frank Attenelo, Srinivas Ramachandran, Min Yu. Single cell multiomic map reveals regulatory landscape of human brain metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1242.
Abstract 1175: Systematic profiling of conditional pathway activation as a new class of cancer dependency
Authors: Liang Chang, Nancy Y. Jung, Adel Atari, Devishi Kesar, Diego J. Rodriguez, Matthew A. Rees, Melissa Ronan, William R. Sellers
Journal: Cancer Research (2023)

Abstract The paradigm of cancer dependencies and targeted therapies has been nearly exclusively focused on inhibiting critical pathways or nodes in cancer. However, conditional activation of signaling pathways as a new source of selective cancer vulnerabilities has not been systematically characterized. In this study, we sought to systematically identify context-specific gene activation lethalities in cancer. We performed lineage-specific mutual-exclusivity (ME) analysis using 69,393 cancer patient genomes in cohorts of AACR-GENIE, TCGA, and Foundation One, across 12 cancer lineages, and identified ME mutation pairs within MAPK, PI3K and WNT pathways indicative of evolutionarily negative selection. To functionally test whether mutual exclusive genetic alterations likely create negative selection pressures in cancer, we developed a lentiviral method to achieve simultaneous ectopic ORF expression ~500 barcoded cancer cell lines for large-scale gain-of-function genetic perturbation. Using this technology, we systematically profiled the pan-cancer vulnerability landscape upon activating 10 key pathway nodes, revealing selective activation dependencies associated with specific biomarkers. We validated the anti-tumor effect of PI3K hyperactivation in PIK3CA/PTEN double-mutant endometrial cancer cell lines. Notably, we find that subsets of APC-mutant colorectal cancers retain active destruction complexes. Upon further depletion of APC or direct expression of β-catenin, the resulting WNT pathway hyperactivation impairs the viability of APC-mutant colorectal cancers in in vitro cell lines and organoids and in in vivo tumor models. Together, our study reveals a new class of conditional gene activation dependencies in cancer. Citation Format: Liang Chang, Nancy Y. Jung, Adel Atari, Devishi Kesar, Diego J. Rodriguez, Matthew A. Rees, Melissa Ronan, William R. Sellers. Systematic profiling of conditional pathway activation as a new class of cancer dependency [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1175.
Abstract 2657: Preclinical model to evaluate the safety and efficacy of PODO83: A monoclonal antibody against podocalyxin that targets tumor growth and metastasis
Authors: Julyanne Brassard, Michael R. Hughes, Pamela Dean, Diana Canals Hernaez, Janella Schwab, Yasmine Lau, Calvin D. Roskelley, Kelly M. McNagny
Journal: Cancer Research (2023)

Abstract Podocalyxin (PODXL) is a highly glycosylated transmembrane sialomucin normally found on the apical free surface of mesothelial, vascular endothelial, luminal mammary epithelial cells, kidney podocytes and pluripotent and hematopoietic stem cells. We were the first to show that PODXL is upregulated on human cancers and an independent predictor of poor prognosis in breast and high-grade serous ovarian carcinoma (HGSOC). We also demonstrated that PODXL expression is crucial for primary tumor growth, local invasion, and experimental metastasis to distant organs. Subsequently, these results were extended to a wide range of other tumor types. We next developed a large series of high-affinity monoclonal antibodies (mAb) to human PODXL and evaluated these for therapeutic activity against the PODXL+ metastatic breast cancer cell line, MDA-MB-231, in xenografted NOD-SCID IL2Rγ-/- (NSG) mice. One of these, PODO83, potently attenuated primary tumor growth and formation of distal metastases. The PODO83 reactive epitope maps to the juxtamembrane stalk domain (non-glycosylated region) of the PODXL core protein. As a promising therapeutic it is imperative to perform toxicity studies and determine if PODO83 adversely affects the function of PODXL on normal tissues. Accordingly, we generated a transgenic mouse strain (C57Bl/6 congenic) replacing 4 of the 8 mouse PODXL-encoding exons with the orthologous human exons (including those encoding the PODO83 epitope). These mice were healthy and we confirmed by immunohistochemistry that they exhibit appropriate PODO83 immunoreactivity in all expected tissues (podocytes, endothelia, etc). Strikingly, administration of PODO83 in vivo at high doses (4 treatments of 5 mg/kg over 14 days) resulted in no overt signs of toxicity. To now fully assess the safety and efficacy profile of the PODO83 mAb in this preclinical humanized mouse model we have developed mouse metastatic tumor cell line expressing human PODXL and will evaluate the ability of PODO83 to inhibit tumor growth and metastasis while sparing normal tissues in vivo. The results from this study will help us advance PODO83 mAb as a safe and effective approach to treating the wide variety of cancer subtypes that express PODXL. Citation Format: Julyanne Brassard, Michael R. Hughes, Pamela Dean, Diana Canals Hernaez, Janella Schwab, Yasmine Lau, Calvin D. Roskelley, Kelly M. McNagny. Preclinical model to evaluate the safety and efficacy of PODO83: A monoclonal antibody against podocalyxin that targets tumor growth and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2657.
Abstract 29: Characterization of a murine intestinal cancer homograft model for therapeutic evaluation
Authors: Jinxi Wang, Leilei Chen, Likun Zhang, Jingqian Zhu, Ludovic Bourre, Jingjing Wang
Journal: Cancer Research (2023)

Abstract Introduction: Intestinal cancers are one of the most lethal malignancies and are responsible for a mass of cancer-related deaths. The discovery of new drugs and therapeutic strategies is underway, and to complement this, the development of superior animal models is required for preclinical studies. Genetically engineered mouse models (GEMMs) mimic de novo human tumor growth within an intact tumor microenvironment and are potent immunocompetent models for studying pathogenesis and immuno-oncology of intestinal cancers. GEMMs with dysfunctional DNA mismatch repair (MMR) genes, like MHL1 and MSH2, manifest intestinal tumors related to microsatellite instability (MSI). However, the low incidence and distinct latency among individuals hamper the application of these GEMMs in preclinical research. In this study, a murine intestinal cancer homograft from GEMMs with MMR deficiency is established to enroll larger cohorts of mice for preclinical studies. Methods: MMR-deficient GEMMs were generated by knockout of Mlh1 gene with a CRISPR-Cas9 system. Intestinal cancer development was investigated in 16 GEMMs. The developed tumor in the intestine of GEMM was isolated by surgery and inoculated into C57BL/6 mice subcutaneously to establish a murine homograft model. The tumor homograft was passaged and expanded in vivo, and stable tumor growth was established over consecutive passages. Histopathological studies were conducted for both the original and passaged tumors. Genomic mutations and gene expression were analyzed by whole exome sequencing and RNA-sequencing, and tumor-infiltrating lymphocytes (TILs) were analyzed by flow cytometry. Therapeutic efficacy of chemotherapies and immune checkpoint inhibitors were evaluated in vivo for tumor growth inhibition. Results: The intestinal tumors or lesions were observed in two of the sixteen Mlh1-KO mice with an incidence of 12.5%. A murine homograft model of small bowel adenocarcinoma was successfully established using the tumor located in jejunum of a Mlh1-KO mouse. This model was stably passaged in vivo with semblable pathological features as the original lesion in Mlh1-KO mice. The various degrees of TILs and response to treatments revealed the potential of this model for in vivo investigation of immune response. Conclusion: Our murine intestinal cancer homograft model presented rapid and stable subcutaneous growth in immunocompetent mice, providing an efficient approach for intestinal cancer researchers and a superior preclinical model for new drug discovery. Citation Format: Jinxi Wang, Leilei Chen, Likun Zhang, Jingqian Zhu, Ludovic Bourre, Jingjing Wang. Characterization of a murine intestinal cancer homograft model for therapeutic evaluation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 29.